59 



The method of procedure is to analyse the soil population by 

 examination of the plant or of the soil and so to determine 

 what org-anism or organisms it is desired to suppress. An investi- 

 gation is then made of the effect of a typical poison (e.g.y 

 carbolic acid) on the organism ; derivatives are systematically pre- 

 pared, and the more toxic are followed up. In this way it has been 

 possible greatly to intensify some of the soil sterilisers previously 

 suggested for horticultural use; e.g., carbolic acid becomes three 

 to five times more effective by chlorination. 



(Note. — This work is carried out by the W. B. Randall assist- 

 ant, and full details for nurserymen are published in the Reports of 

 the Nursery and Market Garden Experiment Station, Cheshunt, 

 Herts.) 



GENERAL AGRICULTURAL PROBLEMS. 



LVI. E. J. Russell. '* British Crop Production." Royal 

 Institution Discourses, Feb. 20th, 1920: Nature, 

 1920. Vol. CV. pp. 176 and 206. 



LVU. E. J. RusshLL. " The Possibility of Increased Crop 

 Production.** (Life and its Maintenance: Blackie 

 & Son). 



LVU I. E. J. Rt'SSELL. " Problems for Research after the 

 War." Conference on the improvement of Agricul- 

 ture. Trans. High. Societv, 1918. Series 5. Vol. 

 XXX. pp. 207-214. 



LIX. E. J. Russell. " Regional Factors in Agricul- 



tural." Geographical Teacher, 1920. No. 56. 



LX. E. J. Russell. " How the Soil was Made." Proc. 

 Armstrong College of Agriculture, Students' Assoc, 

 1917-18. Vol. III. pp. 27-30. 



LXI. E. J. Russell. " Work of the Rothanisted Experi- 

 mental Station.' Journal of the Ministry of Agricul- 

 ture, 1919. Vol. XXVI. pp. 497-507. 



BOOKS. 



ROTHAMSTED MONOGRAPHS ON AGRICULTURAL 

 SCIENCE. 



E. J. Russell. " Soil Conditions and Plant Growth." 4th 

 Edn. (entirely re-cast). Longmans, Green & Co., 1921. 



Xote. — A French translation by M. Georges Matisse is 

 published in the Bibliotheque de culture generale 

 (Flammarion, Paris). A. German translation by 

 Dr. Hans Brehm is published by Steinkopff (Berlin 

 and Dresden) . A translation into Finnish is being 

 arranged. 



Others in preparation dealing with : — 

 Soil Physics. 6. A. Keen. 



Soil Protozoa D. W. Cutler and L. M. Crump. 

 Soil Bacteria. H. G. Thornton. 



Soil Fungi and Algce. VV. B. Brierley, S. T. Jewson 

 and B. M. Bristol. 



